Printable light-emitting compositions

Abstract

Disclosed herein are compositions comprising an electron transport compound, an emissive compound, and an organic solvent. The emissive compound comprises an organic indium complex attached to a nanoparticle core. These compositions are useful in fabricating light emitting devices and can be deposited on a substrate via a printing process.

What is claimed is: 
     
       1. A composition comprising:
 an electron transport compound; 
 an emissive compound; and 
 an organic solvent; 
 wherein the emissive compound is represented by formula (I): 
 
       
         
           
           
               
               
           
         
          wherein:
 core is a nanoparticle core; 
 n is 2; 
 X is a single bond or 
 
       
       
         
           
           
               
               
           
         
          wherein * indicates a point of attachment to the core;
 each 
 
       
       
         
           
           
               
               
           
         
          is independently a first optionally substituted bidentate ligand; 
       
       
         
           
           
               
               
           
         
          is a second optionally substituted bidentate ligand selected from: 
       
       
         
           
           
               
               
           
         
         
           wherein k is 0 or an integer selected from 1 to 20; 
           m is an integer in the range of 1 to 9; 
           p is an integer in the range of 1 to 20, z is 0, 1 or 2; 
           R 1  is selected from alkyl, substituted alkyl, aryl and substituted aryl; 
           R 2  is selected from: alkyl, substituted alkyl, aryl and substituted aryl; 
           each R 5  is independently selected from the following: 
         
       
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         wherein R is independently selected from H or alkyl; and 
         * indicates a point of attachment. 
       
     
     
       2. The composition of  claim 1 , wherein the core comprises a moiety selected from the group consisting of a silsesquioxane, a cyclophosphazene, a triazine, a cyclodextrin, a calizarene, a phthalocyanine, and a silica particle. 
     
     
       3. The composition of  claim 2 , wherein the silsesquioxane comprises a 1,3,5,7,9,11,13,15-octakis(dimethylsilyloxy)pentacyclo-[9.5.1.13,9.15,15.17,13]-octasiloxane. 
     
     
       4. The composition of  claim 1 , wherein the first optionally substituted bidentate ligand is selected from: 
       
         
           
           
               
               
           
         
         and optionally substituted derivatives thereof, wherein ‡ indicates a point of attachment to the Ir. 
       
     
     
       5. The composition of  claim 1 , wherein the first optionally substituted bidentate ligand is a substituted derivative selected from: 
       
         
           
           
               
               
           
         
       
       wherein ‡ indicates a point of attachment to the Ir. 
     
     
       6. The composition of  claim 1 , wherein the first optionally substituted bidentate ligand is selected from: 
       
         
           
           
               
               
           
         
       
       wherein ‡ indicates a point of attachment to the Ir. 
     
     
       7. The composition of  claim 1 , wherein the compound of formula (I) is selected from: 
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
       
       wherein R 3  is 
       
         
           
           
               
               
           
         
       
       wherein k is 0 or an integer selected from 1 to 20, and R 5  can be selected from the following: 
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
       
       and wherein R is independently selected from H or alkyl, and * indicates a point of attachment. 
     
     
       8. A composition comprising:
 an electron transport compound; 
 an emissive compound; and 
 an organic solvent, 
 wherein the emissive compound is represented by one of the following formulas: 
 
       
         
           
           
               
               
           
         
         
           wherein R′ is represented by 
         
       
       
         
           
           
               
               
           
         
         
            or and R″ is represented by 
         
       
       
         
           
           
               
               
           
         
         
            wherein each 
         
       
       
         
           
           
               
               
           
         
         
            is independently a first optionally substituted bidentate ligand, and 
         
       
       
         
           
           
               
               
           
         
         
            is a second optionally substituted bidentate ligand; 
           R 3  is 
         
       
       
         
           
           
               
               
           
         
         
            wherein k is 0 or an integer selected from 1 to 20, and R 5  is independently selected from the following: 
         
       
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
       
       wherein R is independently selected from H or alkyl, and * indicates a point of attachment. 
     
     
       9. The composition of  claim 8 , wherein 
       
         
           
           
               
               
           
         
       
       is selected from: 
       
         
           
           
               
               
           
         
       
       and optionally substituted derivatives thereof, wherein m is an integer in the range of 1 to 9, p is an integer in the range or 1 to 20, z is 0, 1 or 2, R 1  is selected from alkyl, substituted alkyl, aryl and substituted aryl, and R 2  is selected from alkyl, substituted alkyl, aryl and substituted aryl. 
     
     
       10. The composition of  claim 8 , wherein 
       
         
           
           
               
               
           
         
       
       is selected from: 
       
         
           
           
               
               
           
         
       
       and optionally substituted derivatives thereof, wherein ‡ indicates a point of attachment to the Ir. 
     
     
       11. The composition of  claim 8 , wherein the molecular weight of the organic solvent is from about 85 to about 150 g/mol. 
     
     
       12. The composition of  claim 8 , wherein the organic solvent is selected from: ethylene dichloride, chlorobenzene, dichlorobenzene, and a combination thereof. 
     
     
       13. The composition of  claim 8 , wherein the organic solvent comprises 4-methyl-2-pentanone. 
     
     
       14. The composition of  claim 8 , wherein the organic solvent comprises a combination of two compounds selected from: benzene, toluene, 1,2-dichloroethane, chlorobenzene, dichlorobenzene, and a C 1-10  ketone. 
     
     
       15. The composition of  claim 8 , wherein the emissive compound is present at a concentration of from about 0.0001 wt % to about 10 wt %. 
     
     
       16. The composition of  claim 8 , wherein the electron transport compound is present at a concentration of from about 0.1 wt % to about 10 wt %. 
     
     
       17. The composition of  claim 8 , wherein the composition has a viscosity of from about 1 cP to about 20 cP at 20° C. 
     
     
       18. A composition comprising:
 an emissive compound represented by Formula (IV): 
 
       
         
           
           
               
               
           
         
         
           wherein each R 4  is independently selected from: 
         
       
       
         
           
           
               
               
           
         
         an electron transport compound; and 
         an organic solvent. 
       
     
     
       19. The composition of  claim 18 , wherein the composition has a viscosity of from about 1 cP to about 20 cP at about 20° C. 
     
     
       20. The composition of  claim 18 , wherein the organic solvent is dichlorobenzene. 
     
     
       21. The composition of  claim 18  further comprising a hole transport compound. 
     
     
       22. The composition of  claim 21 , wherein the composition comprises:
 from about 0.0001 wt % to about 2 wt % of the emissive compound; 
 from about 0.1 wt % to about 5 wt % of the hole transport compound; 
 from about 0.1 wt % to about 5 wt % of the electron transport compound; and 
 wherein the organic solvent is dichlorobenzene. 
 
     
     
       23. A composition comprising
 an emissive compound represented by Formula (V): 
 
       
         
           
           
               
               
           
         
         
           wherein each R 6  is independently selected from the following: 
         
       
       
         
           
           
               
               
           
         
         an electron transport compound; and 
         an organic solvent. 
       
     
     
       24. The composition of  claim 23 , wherein the composition has a viscosity of from about 1 cP to about 20 cP at about 20° C. 
     
     
       25. The composition of  claim 23 , wherein the organic solvent is selected from dichlorobenzene and 4-methyl-2-pentanone. 
     
     
       26. The composition of  claim 23 , wherein:
 the emissive compound has a concentration of from about 0.0001 wt % to about 5 wt %; 
 the electron transport compound has a concentration of from about 0.1 wt % to about 5 wt %; and 
 the organic solvent is 4-methyl-2-pentanone. 
 
     
     
       27. The composition of  claim 26 , further comprising poly(vinylcarbazole). 
     
     
       28. The composition of  claim 23 , wherein the organic solvent is dichlorobenzene. 
     
     
       29. The composition of  claim 23 , wherein the composition further comprises from about 0.1 wt % to about 5 wt % of a hole transport compound, wherein:
 the emissive compound has a concentration of from about 0.0001 wt % to about 2 wt %; 
 the electron transport compound has a concentration of from about 0.1 wt % to about 5 wt %; and 
 the organic solvent is dichlorobenzene. 
 
     
     
       30. A method of fabricating a light-emitting device comprising depositing a composition according to  claim 1  upon an electrically conductive substrate via an inkjet printer. 
     
     
       31. The composition of  claim 29 , wherein the hole transport compound is poly(vinylcarbazole).